ARCHIVED REPORTS XR0001100 - Laserfiche WebLink

Home Browse Search

h , . 30 December,1999' ' '=AGE-NC Project No 95-0121 Page 4 of 5 _ rirtrogen and phosphorus) necessary to support microbial growth were well below the range necessary for bioremedial activity at the site Copies of the microbial enumeration and physicochemical laboratory reports are included with Appendix C ; A.0 DISCUSSION AND CONCLUSIONS The implications from the findings of the October 1999 investigation are Ground water monitoring data collected in the area of wells MW-1, MW-2, MW-3, MW-4 and MW-7 indicated a ground water flow direction generally toward the north at a gradient of 0 002 ft/ft The flow direction is close to the norm for the area • Ground water elevation at the site decreased an average 1 72 feet between the June 1999 and the October 1999 ground water monitoring events • The elevated concentrations of petroleum hydrocarbons detected an samples collected from wells MW-1, MW-2, MW-3,'Mw-4 and MW-7 indicate that these wells are within or near '. the dissolved petroleum hydrocarbon "core area" of the plume (Figure 4) • The highest`petroleum hydrocarbon concentrations were encountered in the ground water ' samples collected from well MW-3, moderately impacted ground water samples were collected from wells MW-7, MW-2, MW-4 and EW-1 and the least impacted ground water sample was collected from MW-1, demonstrating an elongated, narrow plume oriented ' toward the northeast • From June 1999 to October 1999, an increase in concentrations of dissolved petroleum ' hydrocarbons was quantified in ground water samples collected from wells MW-2, VW-3 and VW-6 (Table 2) The increase in dissolved petroleum hydrocarbons could be attributed toward a minor westward shift in the dissolved plume • A long term trend of increasing ground water elevations has been`previously reported at the site since February 1991 However, the ground water monitoring data has indicated a minor trend of decreasing ground water elevations at the site at least since the March 1999 ground water monitoring event r � 3 • Due to the low gradient at,the site, slight variations in ground water measurements or changes of recharge/discharge of the local ground water could greatly modify ground water flow direction • Based on the,bioenumeration and physicochemical analysis of two ground water samples, natural bioattenuation of the contaminants does not appear likely to be occurring at • detectable levels Due to the lack of bionutnents and specific hydrocarbon'-degrading microorganisms, neither bioremediation nor natural attenuation appears to be an effective s . Advanced CeoEnrironmental,Inc L